Process for dry cleaning



March 17, 1942. I D. P. ALLIS ON 2,275,631

PROCESS FOR DRY CLEANING I Filed Jan. 3, 1940 .FfiO/f FILTER WAS/I'm IDENNIS RALLESON [NVENTUR flag-Kg @W%A Patented Mar. 17, 1942 UNITEDSTATES PAT FF and apparatus for dry cleaning.

At present the usual procedure of dry cleaning by completely dry processconsists of entering fabrics in a washer by weight according to the sizeof the washer and the amount of solvent therein. These fabrics are givena preliminary run of from five to fifteen minutes with a circulatingpump operating. This removes loose or easily soluble soil of solventsolubility. The circulating pump is then stopped and a detergent, orcleaning aid, for the solvent is then applied to the fabrics for thepurpose of aiding in removing imbedded or stubborn soil. This procedureis continued for from ten to thirty minutes according to the amount ofsoil to be sus pended from the fabrics. The circulating pump is thenstarted again for clearing this suspended soil and detergent from thewasher and depositing the same on the screens of a filter in closedcircuit circulation with the washer. This step usually requires from tento thirty minutes dely'completely destroys the surface tension of waterand'for its more remarkable quality of being a very effective detergent,not being greatly changed for this purpose by even concentrated acids. ISulphated. fatty alcohol plays an important part in my process as itserves at least three different purposes. First, it reduces the surfacetension of water to which it is applied, causing it to be a practicalcarrier for itself in combination with dry cleaning fluids of volatilehydrocarbons.- Second, when small quantities of water,

'treatedwith this product, are administered to termined by color .orclarity of the filtered solvent in a sight glass in the circulationcircuit.

The above procedure removes to a great degree soil of solvent'solubilltyfrom the fabric, but leaves the water soluble stains such as,perspiration, fruit juices, and theother stains of like nature.

with the above in mind my invention provides 7 a process adapted toremove water soluble stains while using. the same procedure aboveexplained without changing washers, or solvents, and without theaddition of water proofing agents or solvent soluble moisture carrierstothe solvent.

My process includes the usual procedure above outlined, which employs adetergent for the purpose of a cleaning aid to the solvent, and thenclears the detergentand soil from the circulation by the use of afilter. Then, and this is the new step, I humidify the solvent in thewasher with a detergent solution of fatty alcohol sulphate in waterform, for the purpose of removing stains of watersoluble nature. Thissolution has all the practical advantages of soap and water without thedisadvantages of soap as it does not hy-' drolyze to form an alkalinesolution which is damaging to both fabrics and colors.

Sulphated fatty alcohol is manufactured and sold by difierent chemicalmanufacturers under several trade names such as Arysol, Hyrholol Salt(Orvus W. A. Paste), or Musolite, and other trade names. The product hasbeen used for various purposes, especially for its penetrating qualitiesdry cleaning solvent according to my process, the solution due toretarded surface tension, breaks into small bubbles underagitation ofthe solvent ln circulation, and causes it to stay suspended in this formfor a long enough period of time for its entrance into the washer andwhom absorption by the fabrics. Third, sulphated fatty alcohol possessesremarkable penetrating qualities, and since it is suspended in thesolvent in a very fine state, it is absorbed faster and more uniformlythan plain water, giving the desired results, where needed, withoutusing water repellents to assure even penetration.

The penetrating quality of my sulphated fatty alcohol solution assurespractically all of the solution being absorbed by the fabric,consequently reducing the colloidal moisture content of the. .solvent inuse, to a very fine point. This is of great importance dueto the factthat my process calls for cleaning by the completely dry process first,and then performing a semi-dry process, so that I am able to runsucceeding loads of fabrics without changing machines or solvents.

. This penetrating. quality is also of advantage since it keeps moistureof any amount from leaving the washer and being deposited on the screensof the filter by the pump circulation.

My sulphated fatty alcohol solution, besides reducing surface tensionand possessing great penetrating qualities, has another advantage, thatof possessing and carrying useful detergent action to fabrics inmoisture form. This action accomplished in dry cleaning due to the factthat this solution is not aflected by acid or alkali that may be presentin the area of absorption, or free in the solvent. Also this solutiondoes not affect fabrics or colors that are not affected by plainwater.In other words"! am able to get i soap and water results on watersoluble stains in due to the fact that a very small percentage neardrycleaning without the hazards of water, am

able to hasten the dry cleaning operation, and am able to use minimummoisture.

- exceed six percent of The preferred percent is v fThesesmall amountsadministered to the dry cleaning machine have, by test, proved to havesoil removing qualities of twice the amount of filtered during the dryvent under slight pressure downwardly into the The humidifying detergentsolution according to my invention is a small percentage, about two ipercent,'of sulphated fatty alcohol detergent, and

about 98 percent water. The percentage of water finay vary accordingtothe type of trade sulphated fatty alcohol product used, but the usual3 amount with standards products, such as Arysol or HymololSaltissubstantially as follows:

Arysol or Hymolol Salt ;ounces 2 Y The resulting solution is a detergentthat will .not break down in acids and that will have greatly reducedsurface tension. The amount of solution to be applied by my method tothe dry cleaning solvent will vary according to the controls entranceofthe culation in the pipe amount of soil of water soluble nature to bere-. 1

moved from fabrics, but the amount need never the wefiht of the fabrics.

four percent by weight.

plain water when exposed for the same periodbf time.

My invention also relates to an apparatus for applying 'the'sulphatedfatty alcohol solution to the dry cleaning-solvent. I

In the circuit of the solvent being used and cleaning process, allsoldegrees and with this in mind is immediately before entrance to thewasher. This point of installation of the apparatus is when the solventis circulated and the apparatus is adapted to offset this pressure byvacuum to allow the solution to flow into the circuit by gravity.

In the accompanying drawing of this specification:

Figure 1 is a side elevation of the apparatus, with parts in section,constructed in accordance forming a part with the invention.

Figure 2 is a plan view of the fan-shaped nozzle.

Referring now to thenr wm m which usecharacters of referencedesignatesimilar parts in the various views, I designates a funnel for re isconnected to one of the alined branches of a T 3. A valve 4 is connectedto the other alined branch of the T by a pipe 18 for regulating flowof-the solution to the solvent circulating line. The valve 4 is equippedoutside of the washer itself is under pres- 'sureof varying my apparatusis adapted to inject the solution in the circuit at a point of leastpressure which tion of the solvent by the fan-shaped nozzle. at

the end of the injector nipple lg, located in the solvent flow line anddischarging toward the washer, which la'tteristhe destination of thesol- .vent being circulated. The nozzle serves two purposes, one beingto cause a vacuum to form at this point by the solvent rushing past thenozzle, and the other is that by virtue of the nozzle having a narrowopening it releases the solution in a thin fan-shaped sheet which isbroken into fine particles by agitation of the solvent in circulation.to enter the washerin suspended form while the circulation is inprogress.

It will be understood that the solution must enter the solventcirculation slowly, therefore, the control valve 4 must be set accordingto the velocity of flow which varies according to the size of filter orpump used. The valve cannot beset to gravity flow before installation,but must be set at the beginning of its first use, and according to thespeed of solvent flowing past the outlet of the nozzle. When once set tothe size of the P p, not in use, because the solvent does not back up inthe apparatus.

- ceiving the sulphated fatty alcohol solution. The funnel is equippedat the tom with a pipe 2 which lowest pointin the bot at the bottom witha pipe 5 which is screwed into i a plug 6 which closes the lateralbranch of a. T I.

' The circulating pipe 8 from the filter (not shown) enters one alinedbranch of the T 'I while the circulating pipe l3 to the' washer (notshown) enters the other alined branch of the T I.

A pipe I! is screwed into the plug 6 and connected with the pipe 5. The.pipe I 1 extends the T 3 and is equipped'with a valve it which T ltoiabout the center of the washer In practice the period of timerequired to inject a given amount of the sulphated fatty alcoholsolution to the solvent and assure suspension may vary slightly.Preferably the control valve 4 may be regulated to release the solutionto the solvent circulating line at the rate of one-half pint for everytwenty-five gallons of solvent flowing past the nozzle H. For pumpcirculation of 1200 gallons an hour, it will require approximately fiveminutes to inject, in suspended form, one quart of solution. The samepercentage of injection may be followed as to faster flow of circulationbased on this method of simplified calculation.

It will be pointed out that my sulphated fatty alcohol solution havingmoisture detergent qualities, can be applied to, and suspended in,solvent of less than one-quarter of one percent free fatty acid content.Above this figure solvent has a definite tendency to carry the-selventresidue through the filter and back to the fabrics in the washer.Therefore, solvent. kept below onefourth of. one percent of free fattyacid content proves in practice to be better suited for efiicientcleaning.

In'actual practice, the process is as follows: Thefabrics are placed inthe washer according to weight as is the usual practice. The circulationof the solvent from the washer to the filter and back to the washeris-started and continued for a short period oftime to remove loose orsurface soil of solvent solubility and the circulation is then stopped.Rotation of the cylinder is continuedwhile the solvent detergent-orcleaning aidis added. The rotation of the washer cylinder in thedetergent charged solvent may be continued for from ten to thirtyminutes according to the type of fabric being cleaned and amount of soilto be suspended from the same. Absorbent powder is then added to thesolvent at the washer or'other provided place to be circulated to thefilter to remove the detergent or cleaning aid and the soil suspended I!which rises from the it needs no further attention, even when solutionin the funnel l.

vent shows optical clarity in the sight glass provided for this purpose.At this point my step oi administering the sulphated fatty alcoholdetergent to the solvent at file washer inlet is to be started byplacing the required amount of This solution due. to its rapidpenetration is instantly absorbed by fabrics as it slowly enters thewasher, releasing from the fabrics water soluble stains that have notbeen removed by the'preceding' treatment. The treatment of the fabricsin this manner is allowed to continue for approximately two or threeminutes after the solution has all entered the solvent. This shortperiod of 'time has proved suflicient in practice for complete uniformabsorptionof the solution by the fabrics and the release of stainsaffected, but can be continued for any length of time withoutdetrimental effect to most fabrics. The load of fabrics is then r readyfor extraction and de-odorizing to be done preferably at minimumtemperature since by having used solvent in its most volatile state itis unnecessary to use high temperatures, and in so doing to removethepossibility of wrinkles 2,276,681 by'them, on the filter-screens.Circulation is then started again and continued until the solwillbeiully understood without further explain tion.

what is claimed is: v

In a dry cleaning process. subjecting fabrics in a washer to the actionof a solvent solution containing a detergent, removing the detergentfrom a the solution by filtration, circulating the filtered fattyalcohol detergent to the circulating solvent I solvent solution,introducing sulphated fatty alcohol detergent into the circulatingsolvent solution in a thin fan-shaped sheet at the washer inlet,controlling the release of the sulphated solution to a ratio of one-halfpint to every twenty iive gallons of solvent solution flowing past thepoint of admission of the sulphated alcohol detergent, such controlledadmission and v thin fan-shaped sheet form of the admission eifectingthe breaking up of the sulphated fatty alcohol detergentinto fineparticles by agitation of the solvent solution in circulation so thatthe detergent enters the washer in suspended form while the circulationis in progress, maintaining vfrom extraction and exposure to sudden hightemperatures.

From the abovedescription it is thought that the construction andoperation of the invention the solvent at'less than one quarter of one.per cent free fatty acid content while the sulphated fatty alcoholdetergent is being applied to and suspended in the solvent solution, andreturning the solvent solution with the sulphated fatty alcoholdetergent suspended therein to the washer for further treatment of thefabrics.

' DENNIS P.-ALLISON.--..

